How much room do you have and how much other stuff is running? You get the Spinning Beach Ball of Death when a process is taking longer than the Mac thinks it should.
As you do production, Audacity has to make backup copies of the
Whole Show to allow UNDO to work. Further, Audacity works at a much higher quality standard than normal, so if you think you know what the show sizes are, you're probably wrong.
Go > Computer > Right-click your system drive > Get INFO.

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That's not a particularly good Available number, but that's my "TV Set" and every so often I have to shovel out the dead shows. Many GB each.
Are you using iCloud? Can you stop for a while? Disconnect the network by either pulling the plug or right-click the fan icon > Turn WiFi Off.
Go > Utilities > Activity Monitor. That will give you a display of what's running and how many resources it's taking.
I have an app that slowly gets larger and larger in the background until it starts crowding out other apps. Took me a while to find it. I couldn't figure out why the Mac fan kept going on and getting louder and louder.
Koz